Method of making a surface treating article and such a surface treating article

ABSTRACT

A surface treating article including a surface treating member and a fastener including a fiducial. The present invention also provides a preferred method of making a surface treating article that includes to a method of sensing the location of a fasteners on a surface treating web and thereafter cutting the surface treating web around the fastener to provide a surface treating article.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 09/607210,filed Jun. 30, 2000 now U.S. Pat. No. 6,609,951, now allowed.

TECHNICAL FIELD

The present invention relates to generally to a method of making asurface treating article and such surface treating article, and moreparticularly to a method of sensing the location of a fastener on asurface treating web and thereafter cutting the surface treating webaround the fastener to provide a surface treating article, and such asurface treating article.

BACKGROUND OF THE INVENTION

Machine vision and methods of employing machine vision are known in theart. For example, U.S. Pat. No. 6,005,978 (Garakani) describes anapparatus and method for a two-dimensional search for a model imageusing edge-based and area-based matching. U.S. Pat. No. 5,978,521(Wallack and Michael) describes improved methods for determining acalibration relationship among the imaging reference frames of multiplecameras that acquire images of a common moveable object. U.S. Pat. No.6,064,759 (Buckley et al.) teaches an automatic inspection method andapparatus using machine vision cameras to inspect a three-dimensionalobject.

Adaptive operations enabled by machine vision systems are also known inthe art. For example, U.S. Pat. No. 5,777,880 provides a method andapparatus for correctively guiding an item on a desired path along amaterial. U.S. Pat. No. 5,380,978 (Pryor) describes the use of datums onthree-dimensional objects for the purpose of optically guidedpositioning. U.S. Pat. No. 5,886,319 (Preston et al.) discloses a methodand apparatus for guiding a laser cutter along a path on a patternedmaterial using machine vision.

Various articles and methods for attaching fasteners to articles areknown in the art. For example, U.S. Pat. No. 4,551,189 to Petersondiscloses a friction welding fastener system for fusing a thermoplasticmaterial fastener to a substrate by heat of friction induced through theapplication of rotative and axial forces applied to the fastener. Acavity is formed inwardly of the bottom surface of the thermoplasticbase member and a heat activated adhesive material having a bondingaffinity for both the base material and the substrate material isinserted into the cavity to form a layer having a thickness equal orgreater than the thickness of the base member. The base member isrotated with sufficient rotative and axial forces to cause the heatactivated adhesive layer to adhere to the substrate.

European Patent Application 0 937 544 A2 to Smith discloses a method ofproducing an abrasive treatment disc, whereby the disc is formed from anabrasive material ultrasonically welded to a mounting member.

U.S. Pat. No. 5,931,729 to Penttila et al. discloses a method of spinwelding a fastener to an article and such an article. The fastener ismelt-bonded to the back of the surface conditioning disc. The surfacetreating article comprises a working surface adapted to treat aworkpiece surface, and a back surface, the back surface comprising anopen woven scrim. In a preferred embodiment, the surface treatingarticle has a nonwoven abrasive surface conditioning disc. The Penttilaet al. reference states it is also possible for the surface treatingarticle to be a coated abrasive disc, a polishing pad, a brush, or asimilar surface treating element.

Applicant's copending U.S. patent application Ser. No. 09/551477, filedon Apr. 18, 2000, teaches a method of attaching a fastener to anabrasive article via spin welding and employing an intermediatethermoplastic adhesive layer.

U.S. Pat. No. 3,561,938 to Block et al. discloses an abrasive disk and amethod of making an abrasive disk, which includes impregnating acompressible porous backing sheet matrix having a plurality of segmentsdefining voids with a bonding material, which coats the segments to forma backing sheet. The backing sheet is then placed next to a hub and thetwo are heated and squeezed to compress the backing sheet and cause thebonding material to flow to bond the hub to the backing sheet. The largelamination may then be cut to form a number of the abrasive disks.

Surface conditioning discs having a threaded button bonded to the backside of the disc by an adhesive are available commercially as Roloc™surface conditioning discs from Minnesota Mining and ManufacturingCompany, St. Paul, Minn. These surface conditioning discs have anabrasive member and a fastener attached to the abrasive member by alayer of thermosetting adhesive. The fastener has a base and a threadedportion for attaching to a suitable back-up pad. These surfaceconditioning discs are assembled by first loading the fastener intoheated fixture (typically 200-260° C.), such that the threaded portionof the fastener is held by the heated fixture and the base is exposed.The heated fixture heats the fastener. Next, a layer of thermosettingadhesive is applied to the fastener base, typically by spraying. Afterspraying the thermosetting adhesive, a circular or disc-shaped abrasivemember is centered relative to the fastener held by the heated fixtureand then makes contact with the layer of thermosetting adhesive on thefastener. The abrasive member and fastener are held in a compressiveforce until the layer of thermosetting adhesive has cured. Then, thesurface conditioning disc is removed from the heated fixture.

Threaded fasteners for surface treating articles are taught in U.S. Pat.No. 3,562,968, “Surface Treating Tool,” Johnson et al.

It has been known to cut coated abrasive webs with lasers to form coatedabrasive discs.

SUMMARY OF THE INVENTION

One aspect of the present invention provides a method of making asurface treating article. The method comprises the steps of: a)providing a surface treating web with a fastener attached thereto; b)sensing the position of the fastener on the surface treating web; and c)cutting the surface treating web around the fastener to provide asurface treating article including the fastener.

In one preferred embodiment of the above method, step b) furthercomprises sensing the position of the center of the fastener and step c)comprises cutting the surface treating web around the center of thefastener to provide a surface treating article including the fastenercentered thereon. In another aspect of this embodiment, step c) furthercomprises cutting the surface treating web around the fastener in theshape of a disc. In another preferred embodiment of the above method,step b) is performed using machine vision. In another aspect of thisembodiment, the fastener includes a fiducial, and step b) furthercomprises using the machine vision to determine the position of thefiducial to thereby determine the position of the fastener on thesurface treating web.

In another preferred embodiment of the above method, step c) furthercomprises laser cutting the surface treating web around the fastener toprovide a surface treating article with the fastener thereon. In anotherpreferred embodiment of the above method, the method further comprises:d) advancing the web forward to bring a second fastener attached to thesurface treating web to within a desired region; and e) repeating stepsb) and c) with regard to the second fastener to provide a second surfacetreating article. In another aspect of this embodiment, the method is acontinuous method in which a plurality of fasteners are sequentiallybrought into the desired region, and steps b) and c) are then repeatedwith respect to each of the plurality of the fasteners.

In yet another preferred embodiment of the above method, step c) furthercomprises partially cutting the surface treating web around the fastenerto provide a partially-cut surface treating article with the fastenerthereon, and subsequently separating the surface treating article fromthe surface conditioning web. In another preferred embodiment of theabove method, the method further comprises the step of attaching thefastener to the surface treating web prior to step a). In another aspectof this embodiment, the step of attaching the fastener to the surfacetreating web comprises spin welding. In another aspect of thisembodiment, the fastener comprises a thermoplastic material. In yetanother aspect of this embodiment, the step of attaching the fastener tothe surface treating web comprises placing a thermoplastic layer ofadhesive between the fastener and the surface treating web prior to spinwelding. In another preferred embodiment of the above method, thesurface treating web comprises a coated abrasive web.

Another aspect of the present invention provides an alternative methodof making a surface treating article. This alternative method comprisesthe steps of: a) providing a surface treating web with a fastenerattached thereto; b) thereafter laser cutting the surface treating webaround the fastener to provide a surface treating article, including thefastener.

In one preferred embodiment of the above method, the method furthercomprising the step of sensing the position of the fastener on thesurface treating web prior to step b). In another aspect of thisembodiment, the method further comprises the step of determining theposition of the center of the fastener on the surface treating web priorto step b). In another preferred embodiment of the above method, themethod further comprises the step of determining the position of thecenter of the fastener prior to step b) and step b) comprises lasercutting the surface treating web around the center of the fastener toprovide a surface treating article with the fastener centered thereon.In another aspect of this embodiment, step b) further comprises lasercutting the surface treating web around the fastener in the shape of adisc.

In another preferred embodiment of the above method, the method furthercomprises the step of using machine vision in sensing the position ofthe fastener on the surface treating web prior to step b). In anotheraspect of this embodiment, the fastener comprises a fiducial todetermine the position of the fastener on the surface treating web usingmachine vision. In another preferred embodiment of the above method, themethod further comprises the steps of: c) advancing the web forward tobring a second fastener attached to the surface treating web to within adesired region; and d) repeating step b) with regard to the secondfastener to provide a second surface treating article. In another aspectof this embodiment, the method is a continuous method in which aplurality of fasteners are sequentially brought into the desired region,and steps b) and c) are then repeated with respect to each of theplurality of the fasteners. In- yet another preferred embodiment of theabove method, step b) further comprises partially laser cutting thesurface treating web around the fastener to provide a partially-cutsurface treating article with the fastener thereon, and subsequentlyseparating the surface treating article from the surface treating web.

In another preferred embodiment of the above method, the method furthercomprises the step of attaching the fastener to the surface treating webprior to step a). In another aspect of this embodiment, the step ofattaching the fastener to the surface treating web comprises spinwelding. In another aspect of this embodiment, the step of attaching thefastener to the surface conditioning web comprises placing athermoplastic layer of adhesive between the fastener and the surfaceconditioning web prior to spin welding. In another preferred embodimentof the above method, the surface treating web comprises a coatedabrasive web.

Another aspect of the present invention provides a method of making aplurality of surface treating articles. The method comprises the stepsof: a) providing a surface treating web with a plurality of fastenersfastened thereto; b) sensing the position of at least one of theplurality of fasteners on the surface treating web; and c) cutting thesurface treating web around each of the plurality of fasteners toprovide a plurality of surface treating articles, each including one ofthe plurality of fasteners.

In one preferred embodiment of the above method, each of the pluralityof fasteners is located in a predetermined position forming an array offasteners. In another aspect of this embodiment, the plurality offasteners includes a first fastener and a second fastener, where step b)includes sensing the position of the first fastener and where theposition of the second fastener is determined from the relativepositions of the first fastener and the second fastener. In anotheraspect of this embodiment, step b) further comprises sensing theposition of the first fastener with machine vision. In yet anotherpreferred embodiment of the above method, step b) further comprisesdetermining the position of the center of at least one of the pluralityof fasteners and step c) comprises cutting the surface treating webaround the centers of the plurality of fasteners to provide a pluralityof surface treating articles each including one of the plurality offasteners centered thereon. In another preferred embodiment of the abovemethod, at least one of the plurality of fasteners includes a fiducialto determine the position of the at least one fastener on the surfacetreating web.

In yet another preferred embodiment of the above method, step c) furthercomprises laser cutting the surface treating web around the plurality offasteners to provide a plurality of surface treating articles eachincluding one of the plurality of fasteners thereon. In anotherpreferred embodiment of the above method, step c) further comprisespartially cutting the surface treating web around the plurality offasteners to provide a plurality of partially-cut surface treatingarticles each including one of the fasteners thereon and subsequentlyremoving the plurality of surface treating articles from the surfacetreating web.

In another preferred embodiment of the above method, the method furthercomprises the step of attaching the plurality of fasteners to thesurface treating web in a predetermined array prior to step a). Inanother aspect of this embodiment, the step of attaching the pluralityof fasteners to the surface treating web in a predetermined arraycomprises spin welding. In yet another aspect of this embodiment, thestep of attaching the fasteners to the surface treating web comprisesplacing a thermoplastic layer of adhesive between the fastener and thesurface treating web prior to spin welding. In another preferredembodiment of the above method, the surface treating web comprises acoated abrasive web.

Another aspect of the present invention provides a surface treatingarticle. The surface treating article comprises: a) a surface treatingmember; and b) a fastener on the surface treating member including adrive member, where the drive member includes a distal end, where thedistal end includes a fiducial located thereon.

In another preferred embodiment of the above surface treating article,the fiducial includes a first reflective surface and a non-reflectivesurface. In another aspect of this embodiment, the non-reflectivesurface is at an angle relative to the first reflective surface. Inanother aspect of this embodiment, the distal end of the fastenerincludes a second reflective surface. In yet another aspect of thisembodiment, the non-reflective surface is at an angle relative to thefirst reflective surface and the second reflective surface. In yetanother aspect of this embodiment, the first reflective surface and thesecond reflective surface are parallel.

In another preferred embodiment of the above surface treating article,the surface treating member comprises an abrasive member, and where theabrasive member includes a working surface and a back surface oppositethe working surface. In another aspect of this embodiment, the workingsurface comprises a coated abrasive. In another preferred embodiment ofthe above surface treating article, the working surface comprises anon-woven surface.

Another aspect of the present invention provides an apparatus for makinga surface treating article. The apparatus for making a surface treatingarticle comprises: a) attaching means for attaching a fastener to asurface treating web; and b) cutting means for laser cutting the surfacetreating web around the fastener to provide a surface treating article.

Another aspect of the present invention provides an alternativeapparatus for making a surface treating article. The apparatus formaking a surface treating article comprises: a) a spinwelder forattaching a fastener to a surface treating web; b) machine vision systemto determine the position of the fastener on the surface treating web;and c) a laser to cut the surface treating web around the fastener toprovide a surface treating article with a fastener thereon. In onepreferred embodiment of the above apparatus, the apparatus furtherincludes: d) a web carrier for advancing the surface treating web.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is an isometric view of a preferred embodiment of a surfacetreating article according to the present invention;

FIG. 2 is a side view of the surface treating article of FIG. 1;

FIG. 3 is a top view of the surface treating article of FIG. 1;

FIG. 4 is a schematic side view of an apparatus and method for making asurface treating article according to the present invention;

FIG. 5 is a side view of a preferred apparatus for carrying out themethod of the present invention;

FIG. 6 is an isometric view of the fastener loading station of theapparatus of FIG. 5, prior to loading the fasteners into the spin weldstation;

FIG. 7 is a partially schematic side view of the platen loading thefasteners into the rows of spinwelders;

FIG. 8 is an isometric view of an individual spin welder in theapparatus of FIG. 5, illustrating the fastener spin welded onto thesurface treating web;

FIG. 9 is an isometric view of the exit side of the spin weld station ofthe apparatus of FIG. 5, prior to entering the machine vision andcutting station;

FIG. 10 is a digitally recorded image showing a top view of the fastenerof FIG. 1 on the surface treating web using machine vision;

FIG. 11 is an isometric view of the machine vision and cutting stationof the apparatus of FIG. 5;

FIG. 12 is an isometric view of the separation station of the apparatusof FIG. 5; and

FIG. 13 is an exploded view of the separation station of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of a surface treating article 10 of the presentinvention is illustrated in FIGS. 1-3. FIG. 1 is an isometric view ofsurface treating article 10. FIG. 2 is a side view of surface treatingarticle 2. FIG. 3 is a top view of surface treating article 10.

The surface treating article 10 includes a surface treating member 40and a fastener 12. The relative size of the surface treating member 40to the fastener 12 may be different from what is illustrated in FIGS.1-3.

The surface treating member 40 includes a working surface 42 and a backsurface 44 opposite the working surface 42. The surface treating member40 also includes a peripheral surface 46 extending between the workingsurface 42 and the back surface 44. As illustrated, the fastener 12 isattached to the back surface 44 of the surface treating member 40.Alternatively, the fastener 12 may be attached to the working surface 42of the surface treating member 40.

The surface treating member 40 is illustrated in the shape of a circle.However, surface treating member 40 may be any shape. Preferably, thesurface treating article 40 is a disc, which means it is capable ofrotating about a drive member.

In the illustrated embodiment, the surface treating member 40 is acoated abrasive member 40. The back surface 44 includes a backing. Apreferred backing is one that is thick enough, stiff enough and ruggedenough to withstand the spin welding process. For example, suitablebackings include a resin-impregnated cloth, a polymer-laminated cloth,or a polymer-impregnated paper. Coated abrasive members and their methodof manufacture are well known to those skilled in the art. One exampleof a coated abrasive member 40 is illustrated in U.S. Pat. No.5,766,277, “Coated Abrasive Article and Method of Making the Same,”DeVoe et al., the entire disclosure of which is incorporated herein byreference. Alternatively, the surface treating member 40 could be anon-woven abrasive member 40. A non-woven abrasive member 40 includesfibers needle tacked into a woven scrim. A preferred non-woven abrasivemember is described in detail in U.S. Pat. No. 3,688,453, “AbrasiveArticles,” Legacy et al., the entire disclosure of which is incorporatedherein by reference.

Fastener 12 includes a generally planar base 15 and a drive member 17.The planar base 15 includes a generally planar surface 14 and a secondsurface 16 opposite the planar surface 14. In one preferred embodiment,the planar surface 14 of the fastener 12 has a diameter of approximately3 cm (1.2 in), although larger and smaller fasteners are within thescope of the invention. As illustrated in FIG. 2, second surface 16tapers slightly to be thinner at the outer edge of the fastener 12.Extending from the center of the second surface 16 is drive member 17.One preferred fastener 12 is disclosed in U.S. Pat. No. 3,562,968,“Surface Treating Tool,” Johnson et al., the entire disclosure of whichis incorporated herein by reference. Drive member 17 is configured forattaching the surface treating article 10 to a desired power tool. In apreferred embodiment, the drive member 17 is a threaded stud, which fitswith a corresponding female threaded backup pad (not illustrated). Asuitable back-up pad is available commercially as a Roloc™ disc pad fromMinnesota Mining and Manufacturing Company, St. Paul, Minn.

Preferably, a fiducial 18 is located on the fastener 12. Morepreferably, a fiducial 18 is located on the distal end of drive member17 on distal end surface 19. “Fiducial” is used herein, including theclaims, to describe any line, mark or shape that is used as a standardof reference for sensing a location. For example, fiducial 18 is used tosense the location of fastener 12 on a surface treating web, which isdescribed in greater detail below.

Preferably, fiducial 18 includes first reflective surface 20 and anon-reflective surface 24. More preferably the first reflective surface20 and the non-reflective surface 24 are concentric. Most preferably,the first reflective surface 20 is in the shape of a circle and thenon-reflective surface 24 is in the shape of an annulus surrounding thefirst reflective surface 20. The non-reflective surface is preferably atan angle α measured relative to the first reflective surface 20.Preferably, α is between 20° and 70°. More preferably, α is between 30°and 60°. Most preferably, α is 45°. The distal end surface 19 of thedrive member 17 includes a second reflective surface 22. Preferably, thefirst reflective surface 20 and the second reflective surface 22 areparallel to one another. As illustrated in FIG. 3, the non-reflectivesurface 24 is located between the first reflective surface 20 and thesecond reflective surface 22. Preferably, the non-reflective surface 24and second reflective surface 22 are concentric. More preferably, thesecond reflective surface 22 is the shape of an annulus surrounding thenon-reflective surface 24.

Preferably, fastener 12 is made of a thermoplastic material. Examples ofsuitable thermoplastic materials include nylon and polyamides.Alternatively, fastener 12, may be made of a metal. A suitable metal issteel.

Preferably, the fastener 12 is spin welded directly onto the surfacetreating member 40. Methods of spin welding are known in the art.Generally, spin welding includes placing the fastener 12 and surfacetreating member 40 in contact with one another and then rotating thefastener 12 and surface treating member 40 relative to one another so asto soften the material of the fastener 12 to form a melt bond betweenthe fastener 12 and surface treating member 40. For example, one methodof spin welding a fastener to a surface treating article is disclosed inU.S. Pat. No. 5,931,729 to Penttila et al., the entire disclosure ofwhich is incorporated herein. The preferred spin welding method for thefastener 12 and surface treating member 40 is described below.

Another suitable method of attaching the fastener 12 to the surfacetreating member 40 is disclosed in U.S. patent application Ser. No.09/551,477 (Fritz et al.), filed on Apr. 18, 2000, the entire disclosureof which is incorporated herein. This patent application generallydiscloses a method of attaching a fastener to a surface treating memberby first placing a layer of adhesive between the fastener and surfacetreating member. Then, the fastener and surface treating member are spinwelded together with the layer of adhesive between them, so as to softenthe layer of adhesive. Upon cooling, the layer of adhesive forms a bondbetween the fastener and the surface treating member 40. Preferably, theadhesive is a thermoplastic adhesive.

Another suitable method of attaching the fastener 12 to the surfacetreating member is by using a layer of thermosetting adhesive betweenthe fastener 12 and the surface treating member 40, which is cured byheat. However, the method of attaching the fastener 12 to the surfacetreating member 40 is not critical and the fastener 12 may be attachedto the surface treating member 40 in any way known to those skilled inthe art.

FIG. 4 is a schematic side view of an apparatus 50 and method for makinga surface treating article 10 according to the present invention. Theapparatus 50 includes an unwind assembly 52, a fastener loading station60, a spin weld station 70, a machine vision and cutting station 80, aseparation station 90, and a wind assembly 88. The surface treating web30 is moved intermittently through the apparatus 50 as it progressesthrough each station. Preferably, the time a portion of the web 30spends at each station is approximately equal to allow a smooth and evenprogression of the web 30 through apparatus 50.

As illustrated in FIG. 4, a length of surface treating web 30 isinitially provided in unwinding assembly 52 on surface treating web roll54 in roll form. Preferably, roll 54 includes a brake. The brake is setto inhibit roll 54 from freely rotating, but instead to rotate with aslight amount of resistance. The web 30 progresses from roll 54 to anassembly formed by upper roll 56 and lower roll 57. The web 30 thenprogresses to the fastener loading station 60 of the apparatus 50.Platen 62 is located above the web 30. The fasteners 12 are loaded ontothe platen 62 in predetermined locations to form two rows of fasteners12. Platen 62 includes a vacuum (not shown) and vacuum holes 63, whichhold the fasteners 12 in their predetermined locations while they arebeing transferred to the spin welders 74 in spin weld station 70. Therelative locations of the fasteners 12 on the platen 62 are arranged tocoordinate with the locations of the two rows of spin welders 74 in spinweld station 70. Platen 62 delivers the two rows of fasteners 12 to thespin weld station 70 of the apparatus. While the platen 62 delivers thefasteners 12 to the spin weld station 70, the web 30 advances forward toprovide an area for the fasteners 12 to be spin welded and stops underthe spin weld station 70. The fasteners 12 are lifted into chucks 76 onthe bottom ends of the spin welders 74 and the platen 62 retreats backto its original position to receive more fasteners 12. Plate 75 islocated below the web 30 opposite the spin welders 74. Plate 75 moves upvertically to support the web 30 just prior to when the spin welders 74attach fasteners 12 to the web 30. The spin welders 74 spin weld thefasteners 12 onto the surface treating web 30. The web is stationarywhile the fasteners 12 are spin welded onto the web. Afterwards, plate75 moves down vertically away from the web 30.

After the fasteners are spin welded, the web advances forward to themachine vision and cutting station 80 of the apparatus 50. The web 30comes to a stop to remain stationary under the machine vision andcutting station 80. The machine vision system 82 senses the position ofthe fasteners 12 on the web 30 that were spin welded onto the web at theprevious station. Next, the laser 84 partially cuts the web 30 aroundeach of the fasteners 12 to form partially cut surface treating articles10. The web 30 then starts again and proceeds from the machine visionand cutting station 80 to the separation station 90 of apparatus 50. Thehollow cylinders 94 of the upper ram assembly 91 mechanically separatethe partially cut surface treating articles 10 from the web 30. Theseparated surface treating articles 10 fall into the receiving bin 86.The web progresses from the separation station 90 to the nip assemblyformed between the upper and lower web rolls 68, 69. Finally, theremaining web then progresses from the nip assembly formed between theupper and lower web rolls 68, 69 to the wind assembly 88, where theremaining web 30 is wound around the surface treating web roll 102.Preferably, roll 102 includes a motor for winding the web around theroll.

Preferably, the surface treating web 30 is an abrasive web. Morepreferably, abrasive web may be either a coated abrasive web or a nonwoven abrasive web. Preferably, the web 30 is between 2 and 60 incheswide. More preferably, the web 30 is between 15 and 36 inches wide.However, the web width could vary depending on the number and size offasteners 12 attached to the web 30 and the size of the finished surfacetreating article 10.

Preferably, portions of the web 30 move intermittently between theindividual stations at approximately the same speed. Preferably, theaverage speed of the web 30 is between 5 and 150 inches/minute throughapparatus 50, and more preferably between 25 and 75 inches/minutethrough apparatus 50. The average speed is calculated taking intoaccount the web acceleration from a stationary position at one stationand web deceleration to a stationary position at an adjacent station.

FIG. 5 illustrates one preferred embodiment of apparatus 50. The unwindassembly 52 and wind assembly 88 are not illustrated. The apparatus 50includes the fastener loading station 60, spin weld station 70, machinevision and cutting station 80, and separation station 90. FIGS. 6-13illustrate each of these stations of the apparatus 50 in more detail.

As seen in FIG. 5, frame 51 extends between the fastener loading station60 and the separation station 90. Upper web roll 56 and lower web roll57 are mounted on one end of the frame 51. Upper web roll 68 and lowerweb roll 69 are mounted on the opposite end of the frame 51. Two upperbelts 58 are wrapped around opposing ends of upper roll 56 and upperroll 68. Two lower belts 59 are wrapped around opposing ends of lowerroll 57 and lower roll 69. Upper web rolls 56, lower web rolls 57, upperbelts 58, and lower belts 59 form a web carrier for moving the web 30through apparatus 50. As upper rolls 56, 68 and lower rolls 57, 69 arerotated, upper and lower belts 58, 59 progress the web 30 through thefastener loading station 60, the spin weld station 70, the machinevision and cutting station 80, and the separation station 90 ofapparatus 50. Preferably, the upper and lower belts 58, 59 are incontact with the opposing edges of the web 30. However, manyarrangements for moving web 30 through the apparatus 50 are within theinvention. For instance, the web carrier may include a drive shaft 68driven by a motor, upper and lower rolls 56, 57, which are both idle,and upper and lower belts 58, 59. Drive shaft 68 may be connected tolower roll 69, and both drive shaft 68 and lower roll 69 will drive thebelts 58, 59 to move the web 30 through the apparatus 50 in thedirection of the arrow.

In the spin weld station 70, spin welder stand 72 holds a plurality ofspin welders 74 directly above the moving web 30. In the machine visionand cutting station 80, the stand 83 holds the machine vision system 82and laser cutting system 84 directly above the moving web 30. In theseparation station 90, stand 110 holds the separation apparatus 99. Theseparation apparatus 99 includes an upper ram assembly 91 and a web backup assembly 92. The upper ram assembly 91 is positioned above the movingweb 30. The web back up assembly 92 is located below the moving web 30opposite the upper ram assembly 91.

FIG. 6 illustrates the fastener loading station 60 and the spin weldstation 70 in more detail. The web 30 progresses through an assemblyformed between the upper and lower roll 56, 57. The two upper belts 58rotate about the ends of upper web roll 56. Two lower belts 59 rotateabout the ends of lower web roll 57. As the belts 58, 59 are rotated byupper and lower rolls 56, 57, the web 30 progresses through theapparatus 50.

In the fastener loading station 60, the fasteners 12 are loaded ontoplaten 62 in predetermined locations. A vacuum (not shown) holds thefasteners 12 in their respective locations. Preferably, the fastenersare arranged relative to each other to coordinate with the location ofthe chucks 76 in the spin welders 74 located in stand 72. Preferably,the fasteners are arranged in a first array 120 and a second array 122(as shown in FIGS. 9 and 11). More preferably, each array 120, 122 is arow of fasteners, with each row offset from the other. Each row isillustrated as having five fasteners. However, more or less fastenersmay be used depending on the number of spin welders 74 in stand 72.

As illustrated, stand 72 may hold up to a total of thirteen spin welders74. More or less spin welders 74 may be used depending on the size ofthe finished surface treating articles 10 and the width of the web 30.The first row of spin welders 74, closest to the fastener loadingstation 60, may contain up to six spin welders. However, for clarity inthe drawing, only two spin welders 74 are illustrated. The second row ofspin welders 74, located opposite the first row, may contain up to sevenspin welders 74. However, for clarity, only two of the seven spinwelders 74 are shown. The second row of spin welders may be seen moreclearly in FIG. 9. Stand 72 includes a vertical stationary bar 78located both in front and behind each spin welder 74. However, forclarity in the drawing, some of the bars 78 have been removed. As thespin welders 74 move vertically to spin weld a fastener 12 onto the web30, the spin welder 74 slides up and down stationary bars 78. Horizontalsupport bars 79 support the ends of the stationary bars 78 within stand72.

FIG. 7 is a schematic illustration of how the platen 62 loads thefasteners 12 into the spin welders 74. The chucks 76 of the spin welders74 are illustrated in cross-section to show the grip arms 77 within thechucks 76. In position A, the fasteners 12 are loaded onto the platen 62in their predetermined positions. The predetermined positions coordinategenerally with the relative locations of the chucks 76 of the spinwelders 74. After the fasteners 12 are loaded, the vacuum (not shown) isturned on to hold the fasteners 12 in their respective positions throughvacuum holes 63. The platen then moves to position B, which is locateddirectly below the spin welders 74. The fasteners 12 are now in positiondirectly below the chucks 76 of the spin welders 74. Next, the platenmoves into position C, inserting the drive members 17 of fastener 12directly into the grip arms 77 of the chuck 76. The vacuum is thenturned off to release the fasteners 12. The grip arms 77 are preferablyspring loaded to grasp the drive members 17 when the platen 62 movesback to position A to receive more fasteners 12. Mechanisms for movingthe platen 62 as described herein are well known to those skilled in theart.

FIG. 8 illustrates one of the spin welders 74 in stand 72 (shown in FIG.6) spin welding a fastener 12 onto the web 30. The spin welder 74includes a rotary motor 150 and vertical drive mechanism 152. Drivemechanism 152 is attached to support bar 79 (not shown). In a preferredembodiment, the drive mechanism 152 is an air cylinder. Two stationarybars 78 extend from the support bar 79 on either side of the spin welder74. The motor 150 is mounted via a slidable frame 140 to the stationarybars 78 to allow the slidable frame 140 and motor 150 to be drivenvertically by the rod 154 extending from the air cylinder 152. Extendingfrom the motor 150 is a first shaft 157. The first shaft is coupled to asecond shaft 160 by coupling 158. Mounted at the distal end of thesecond shaft 160 is a chuck 76 for holding the fastener 12. It is thusseen that the motor 150 spins first shaft 157, second shaft 160, andchuck 76; and that all of these components, along with the slidableframe 140, are raised and lowered together in response to actuating thedrive mechanism 152.

Chuck 76 can be any suitable fixture that will hold the fastener 12during the spin weld operation. Chuck 76 must grip the fastener 12securely enough to avoid slippage of the fastener 12 within the chuck 76when the fastener is spun against the surface treating web 30. Chuck 76should also provide for easy release of the fastener 12 after the spinweld process. Chuck 76 thus may include moveable elements for grippingand releasing the fastener 12, as is well known in the art.

The forward travel of the web 30 stops below the spin welders 74 byupper and lower belts 58, 59. Plate 75 located below the web 30(illustrated in FIG. 4) raises up to support the web 30 opposite thespin welders 74. While the web 30 is held stationary below the spinwelders 74, the spin welders 74 spin weld the fasteners 12 to the web30. After the fasteners 12 are attached to the web 30, plate 75 lowersto allow the web 30 to move to the machine vision and cutting station.

A preferred method of spin welding the fastener 12 to the surfacetreating web 30 is as follows. In general, the spin weld methodcomprises the steps of holding stationary the surface treating web 30,mounting the fastener 12 in a chuck 76 to be driven by the spin welder74, accelerating the chuck 76 and fastener 12 to the desired rotationalspeed, activating the drive mechanism 152 to move the planar surface 14of the fastener 12 into contact with the surface treating web 30,applying sufficient force between the fastener 12 and surface treatingweb 30 while the fastener is spinning to achieve a frictionaltemperature required to soften the planar surface 14, allowing the chuck76 and fastener 12 to stop rotation, maintaining force between thefastener 12 and surface treating web 30 while the planar surface 14 ofthe fastener 12 sufficiently cools to form a bond between the fastener12 and surface treating article web 30, and releasing the fastener 12from the chuck 76. The surface treating web 30 is mechanically heldstationary between the upper and lower belts 58, 59 (not shown) to keepthe web 30 stationary during the spin welding process. Optionally,adhesive may be placed between the planar surface 14 of the fastener 12and the surface treating web 30 prior to spin welding them together soas to form an adhesive bond between the fastener 12 and surface treatingweb 30.

The following parameters are preferred when spin welding a nylonfastener 12 on a coated abrasive web with a backing comprising aresin-impregnated cloth or polymer-backed cloth. The parameters found toaffect the strength of the melt-bond between the fastener 12 and surfacetreating web 30 are as follows. The force that the chuck 76 applies tothe system is preferably between about 250 and 1100 lb., more preferablybetween about 300 and 700 lb., and most preferably between about 350 and500 lb. The speed of the motor 150 is preferably between about 500 and8000 RPM, more preferably, between 2000 and 6000 RPM, and mostpreferably, between about 2500 and 4500 RPM. The spin time is preferablybetween about 0.05 seconds and 0.6 seconds. More preferably, the spintime is preferably between about 0.2 seconds and 0.45 seconds. The spintime is a measurement of how long the rotary motor 150 is maintainedunder power from the time the chuck 76 is positioned vertically withinapproximately 0.125 inches or less from the web 30 (essentially at thetime of contact between the fastener 12 and the web 30) and ends withthe command to remove power from the motor 150 after the fastener 12contacts the surface treating web 30. After the power is removed fromthe rotary motor 150, the force between the fastener 12 on the web 30must be maintained for a period of dwell time to form a sufficient bondbetween the fastener 12 and the web 30. Preferably, the dwell time isbetween 0.1 and 1 seconds, and more preferably, between 0.2 and 0.5seconds.

FIG. 9 illustrates the web 30 and fasteners 12 attached to web 30 as itexits the spin weld station 70 in the direction of the arrow to enterthe machine vision and cutting station 80. The first row of spin welders74 attach fasteners 12 arranged in a first array 120. The second row ofspin welders 74 simultaneously attach fasteners 12 arranged in a secondarray 122. Each array 120, 122 contains a first fastener 124, a secondfastener 126, a third fastener 128, a fourth fastener 130, and a fifthfastener 132. Preferably, the fasteners in each array 120, 122 arespaced equally from each other. The spin welding stand 72 may hold up tothirteen spin welders, thus allowing thirteen fasteners to besimultaneously spin welded to the web. However, for clarity the web isillustrated as having only ten fasteners welded to it in the first andsecond arrays 120, 122. The first and second arrays 120, 122 are locatedsome distance relative to one another and offset from one another sothat other arrays of fasteners may be spin welded between them, as theweb 30 progresses through the spin weld area 70. The arrays of fasteners12 are arranged so as to optimize the number of surface treatingarticles formed from the web 30 and to reduce web waste.

Because the spin welders 74 are mounted in fixed positions in the stand72, the fasteners 12 are spin welded in predetermined positions on theweb. This is convenient for sensing the positions of the fasteners 12and cutting around the fasteners 12 on the web 30 to make surfacetreating articles 10.

When the web enters the machine vision and cutting station 80,illustrated in FIG. 11, the machine vision system 82 scans the web 30 tosense where the fasteners 12 are located on the web 30. Preferably, themachine vision system 82 includes two cameras, which take digital imagesof the web 30 in two different locations. More preferably, the firstcamera takes a digital image of the first array 120 of fasteners 12located on the web 30 and the second camera takes a digital image of thesecond array 122 of fasteners 12 located on the web 30. Most preferably,the first camera takes a digital image of the first fastener 124 in thefirst array 120 and the second camera takes a digital image of the fifthfastener 132 in the second array 122. The cameras send the output to themachine vision system computer processor, which processes the images todetermine the location of the fasteners 12. The computer processor thendetermines the coordinates of the first fastener 124 in first array 120and the fifth fastener 132 in the second array 122. These coordinatesare then sent to the laser system, which directs where the laser 84 isto cut. Laser 84 then cuts the web around the each of the fasteners toform surface treating articles 10, as illustrated in FIG. 11.Preferably, the computer processor may determine the coordinates of thecenters of the fastener 12 to allow laser 84 to cut around the centersof the fasteners 12 to form surface treating articles with fasteners 12centered thereon.

FIG. 10 is a digitally recorded image showing the view of a fastener onthe surface treating web using the camera in the machine vision system82. The fiducial 18 located on the distal end of the drive member isused to sense the position of the fastener on the web 30. Specifically,the machine vision system searches for the pattern the fiducial 18 onthe fastener 12 creates. The machine vision system camera includes aring light, which shines directly onto the web 30 and fastener 12 fromaround the camera. The camera in the machine vision system records thedigital image illustrated in FIG. 10. The camera image is preferably ina gray scale image. The areas of the fastener that are perpendicular tothe direction of the light will reflect the light back, producing whiteareas. The areas of the fastener that are at an angle other thanperpendicular to the direction of the light, will reflect the lightaway, producing black or gray areas. The fiducial 18 includes a firstreflective surface 20 and non-reflective surface 24. The term“reflective” refers to the surface reflecting light back to the camera.The term “non-reflective” refers to the surface reflecting light awayfrom the camera. The first reflective surface 20 is preferablyperpendicular to the direction of the light and preferably parallel tothe web direction. The non-reflective surface 24 is preferably at someangle other than perpendicular to the direction of the light and notparallel to the web direction. Preferably, the non-reflective surface 24is at angle a between 20° and 70° measured relative to the firstreflective surface 20. More preferably, α is between 40° and 50°. Mostpreferably, α is 45°. The distal end surface 19 of the distal end of thedrive member 17 includes the second reflective surface 22, which ispreferably perpendicular to the direction of the light and parallel tothe web direction. As a result, the first and second reflective surfaces20, 22 reflect light to the camera, producing white areas, and thenon-reflective surface 24 does not reflect light to the camera,producing a black area. Since the non-reflective surface 24 is locatedbetween the first and second reflective surfaces 20, 22, this creates aclear image for which the machine vision 82 system scans.

Preferably, the first reflective surface 20 is in the shape of a circleand reflects back a white circle. Preferably, the non-reflective surface24 is in the shape of an annulus surrounding the first reflectivesurface 20 and causes a black annulus centered around the white circle.Preferably the second reflective surface 22 is in the shape of anannulus surrounding the non-reflective surface 24 and reflects back awhite annulus centered around the black annulus. The combination ofthese three features in the image creates a pattern of a “bull's eye”which the machine vision system scans for on the web 30. Using thisimage, the computer can then determine the location of the fastener 12on the web. Once the position of the fastener 12 is determined, theposition of the fastener is sent to the laser control system. Then, thelaser is directed to cut around the fastener to form a surface treatingarticle 10. Preferably, machine vision system computer may determine theposition of the center of the fastener using the same image. Once theposition of the position of the center of the fastener 12 is determined,the output is sent to the laser control system. Then, the laser isdirected to cut around the center of the fastener to form a surfacetreating article with the fastener 12 centered thereon.

Any commercially available machine vision system 82 capable of obtainingthe conditions described herein may be used, such as the Acuity™ VP-2000available from RVSI Acuity, Inc. located in Nashua, N.H. Anothersuitable machine vision system 82 includes DVT Series 600 available fromDVT, Inc. located in Norcross, Ga.

FIG. 11 illustrates the machine vision and cutting station 80 of theapparatus 50. Preferably, the web 30 advances until the arrays 120, 122of fasteners 12 that were simultaneously attached by spin welders 74 onthe web 30 are underneath the machine vision and cutting system. The webthen stops and is held stationary while the locations of the fasteners12 on the web are sensed and while the laser 84 cuts the web 30 aroundthe fasteners.

The laser 84 cuts around the fasteners 12 located on the web 30 to formsurface treating articles 10. The laser 84 is illustrated as starting tocut around the first fastener 124 of the first array of fasteners 120.The laser will then continue to cut around the second fastener 126 andproceed to the third, fourth and fifth fasteners 128-132 in the firstarray 120 before proceeding to cut around the fasteners 124-132 in thesecond array 122.

Each fastener 12 may be sensed individually as mentioned above prior tocutting around each fastener 12. However, it is also possible to senseonly one or some of the fasteners 12 within an array of fasteners andthen to determine location of all of the fasteners 12 in the array priorto cutting around each fastener within the array. For instance, if anarray of fasteners included only a first fastener and a second fastenerand it is known that the first fastener and second fastener are locateda certain distance and direction from one another on the web 30, thenonce the position of the first fastener has been sensed, the position ofthe second fastener may be determined from the relative positions of thefirst fastener and the second fastener.

Referring to FIGS. 9 and 11, the fasteners 12 in each array 120, 122were simultaneously spin welded to the web 30 by spin welders 74.Therefore, the positions of the fasteners in the arrays 120, 122coordinate with the relative positions of the chucks 76 in the spinwelders 74 in stand 72. Preferably, the chucks 76 are spaced equally sothat the fasteners are spaced equally from each other in one direction.Because the distance and direction between the fasteners in arrays 120,122 are known and the total number of fasteners 12 in each array 120,122 are known, then the position of each of the fasteners 12 in thefirst and second arrays 120, 122 may be determined by: 1) sensing thelocation of the first fastener 124 in the first array 120 on the web 30;2) sensing the location of the fifth fastener 132 in the second array122 on the web 30; and 3) calculating the position of each of thefasteners 12 in the arrays 120, 122 based on the known factors. Once theposition of each of the fasteners 12 within the arrays 120, 122 havebeen determined, the laser 84 will cut around the fasteners to formsurface treating articles 10. Alternatively, if the cutting pattern forall of the fasteners 12 in the arrays 120, 122 is entered into the lasercontrol system, then the laser may cut that pattern after it receivesthe sensed locations of the first fastener 124 in the first array 120and the fifth fastener 132 in the second array 122 on the web 130,without calculating the position of each of the fasteners 12 in thearrays 120, 122.

Preferably, the fiducial 18 is centered relative to the drive member 17.The benefit of having the fiducial 18 centered relative to the drivemember 17 is that the laser 84 may cut a nearly perfectly centeredsurface treating article with the fastener 12 centered thereon. Thisallows for final surface treating article which will wear more evenlyover time in comparison to a surface treating article having a fastenerthat is not centered.

Preferably, the laser partially cuts the web 30 around the fasteners 12to form a partially cut surface treating article 10. Preferably, thelaser 84 cuts partially through the thickness of the web 30 so that thesurface treating article 10 stays with the web until it is received atthe separation station 90. If the surface treating web is a coatedabrasive web, the laser preferably cuts through the backing on the backsurface, but not the abrasive coating on the working surface of the web.Alternatively, the laser 84 may cut all the way through the web 30 toseparate the surface treating articles 10 from the web completely, andthus, eliminating the need for the separation station 90.

A suitable laser system includes a laser generator coupled to requiredservices, a beam delivery system, and a work surface containing orattached to an exhaust system. Preferably, the beam delivery system oflaser 84 includes the following parameters: a galvanometer-based orother scanning optical-based system, minimum of 50 mm aperture, afocused beam size of less than 300×10⁻⁶ m in diameter, minimum fieldsize of 15 inches, power capability of 2500 watts, speed of mirrors todirect the beam at a speed of between 300 and 2000 mm/sec (measured onthe working surface) and acceleration greater than 200 g (measured onthe working surface). Preferably, the beam delivery system is acompletely reflective optical system, as opposed to a transmissiveoptical system. Preferably, the suitable laser system includes a totalsystem accuracy of better than plus or minus 0.004 inches in any fieldposition and for the lifetime of the equipment.

Any commercially available lasers 84 capable of obtaining the conditionsdescribed herein may be used, such as the LPM-2500 and LPM-1000available from LasX Industries, Inc. located in White Bear Lake, Minn.

After the surface treating articles 12 are partially cut, the webadvances to the separation station 90 of the apparatus 50 illustrated inFIG. 12. The separation apparatus 99 is mounted to stand 110. Theseparation apparatus 99 includes an upper ram assembly 91. The upper ramassembly, which is positioned above the moving web 30, moves verticallyto mechanically remove the partially cut surface treating articles 10for the web 30. After the surface treating articles 10 are mechanicallyremoved from the web, they fall into bin 86 (not illustrated).

FIG. 13 illustrates an exploded view of the separation apparatus 99,which is convenient for discussing the different components of theseparation apparatus 99. The separation apparatus 99 includes an upperram assembly 91 and a web back-up assembly 92. The upper ram assembly 91includes a stationary bracket 98, which is mounted to stand 110 (seeFIG. 12), and ram plate 93. Drive mechanism 95 is supported bystationary bracket 98. In a preferred embodiment, the drive mechanism 95is an air cylinder. Shafts 96 extend from the drive mechanisms 95.Flange couplings 97 attach the shafts 96 to the ram plate 93. The drivemechanism 95 and shafts 96 move the ram plate 93 vertically. Extendingfrom the bottom of the ram plate 93 opposite the couplings 97 arecylinders 94. The arrangement of cylinder 94 on ram plate 93 correspondsto the arrays of partially cut surface treating articles 120, 122.Preferably, the cylinders 94 are hollow and sized to match the perimeterof the partially cut surface treating articles 10. The upper ramassembly 91 is illustrated in the extended position, as if tomechanically separate the partially cut surface treating articles 10 outof the web. In this position, cylinders 94 extend through the web 30 andinto holes 101 in plate 100. However, in this exploded view the upperram assembly 91 and back up assembly 92 have been separated forillustrative purposes.

Web back-up assembly 92 is located below the upper ram assembly 91 andbelow the moving web 30. Web back-up assembly 92 includes plate 100having a plurality of holes 101 sized to receive the cylinders 94 of theupper ram assembly 91. Web back-up assembly 92 includes a frame 105,which supports plate 100. Mounted inside frame 105 just below plate 100are two back up plates 102. The two back up plates pivot about pivots103. Two transfer chutes 104 are mounted below the two back up plates102 inside frame 105. The transfer chutes 104 are fixed within the frame105 and do not move. When the upper ram assembly 91 pushes down onto theweb to mechanically separate the partially cut surface treating articles10 from the web 30, the back up plates 102 are pivoted up to contact thecylinders 94 as they move through holes 101 in plate 100. After thepartially cut surface treating articles 10 are mechanically separatedfrom the web 30, they fall onto the plate 102. Next, the back up plates102 pivot about pivots 103 into the down position, as illustrated inFIG. 13. The surface treating articles 10 then slide down onto thetransfer chutes 104 and are directed into bin 86 (See FIG. 4.)

After the surface treating articles 10 are removed from the web 30 , theweb 30 proceeds from the separation station 90 of the apparatus 30 tothe wind assembly 88, which was illustrated in FIG. 4. Wind assembly 88includes the surface treating web roll 89. The remaining web 30 is woundaround surface treating web roll 89.

Preferably, the stations 52, 60, 70, 80, 90, and 88 of apparatus 50 arecoordinated such that the web 30 stops and each station does its stepsimultaneously at different portions of the web. However, stations 52,60, 70, 80, 90, and 88 may be each independent or could be combined in avariety of sequences.

Although the cutting means illustrated for apparatus 50 is a laser,other cutting means may be used instead. For instance, suitable cuttingmeans includes die cutting, water jet cutting, or ultrasonic cutting. Asmentioned above, the fasteners 12 may be attached to the web 30 bymethods other than spin welding.

Although it is preferable to use machine vision in combination with thelaser to perform the inventive method, other combinations are within theinvention, such as combining machine vision with the other suitablecutting means mentioned above or combining other sensing means withlaser cutting.

The present invention has now been described with reference to severalembodiments thereof. The foregoing detailed description and exampleshave been given for clarity of understanding only. No unnecessarylimitations are to be understood therefrom. All patents and patentapplications cited herein are hereby incorporated by reference. It willbe apparent to those skilled in the art that many changes can be made inthe embodiments described without departing from the scope of theinvention. Thus, the scope of the present invention should not belimited to the exact details and structures described herein, but ratherby the structures described by the language of the claims, and theequivalents of those structures.

What is claimed is:
 1. A surface treating article, comprising: a) asurface treating member, and b) a fastener on said surface treatingmember including a drive member, wherein said drive member includes adistal end, wherein said distal end includes a fiducial, wherein saidfiducial includes a planar first reflective surface, a non-refleclivesurface, and a planar second reflective surface, wherein the secondreflective surface occupies a different plane than the first reflectivesurface, and wherein the non-reflective surface is at an angle relativeto the first reflective surface and the second reflective surface. 2.The surface treating article of claim 1, wherein said first reflectivesurface and said second reflective surface are parallel.
 3. The surfacetreating article of claim 1, wherein the surface treating membercomprises an abrasive member, and wherein said abrasive member includesa working surface and a back surface opposite the working surface. 4.The surface treating article of claim 3, wherein the working surfacecomprises a coated abrasive.
 5. The surface treating article of claim 3,wherein the working surface comprises a non-woven surface.